Ink tank cap



FIG. 1 is a front, top, and right side perspective view of an ink tank cap showing our new design;

FIG. 2 is a rear, bottom, and left side perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a right side view thereof; and,

FIG. 8 is a left side view thereof.

The features shown in broken lines in the drawings depict environmental subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for an ink tank cap, as shown and described. 